Improved grindino-mill



that Stairs ALMON THWING, OF HOPEDALE, AND CHARLES H. FOWLER, OF

WEST ROXBURY, MASSACHUSETTS.

Letters Patent No. 89,609, dated May 4,1869.

IMPROVED GRINDING-MILL The Schedule referred to in these Letters Patent and making part of the same.

To all persons to whom these presents may come:

Be it known that we, ALMON Tuwme, of H opedale, in the county of Worcester, and CHARLES H. FOWLER, of "West Roxbury, of the county of Norfolk, and State of Massachusetts, have made a new and useful invention, having reference to Mills for Grinding or Pulverizing Substances; and we do hereby declarethe same to.-be fully described in the following specification, and represented in the accompanying drawings, of which- Figure 1 denotes a top view Figures 2 and 3 are side elevations; and

Figure 4 a transverse section of a mill, embodying our invention;

Figure 6 is a top view of its circular-grooved runner.

Figure 5 is an under side view of the circular-grooved cap-plate;

In the drawings-- A denotes-the frame of. the mill.

.NVithiu the said frame is a vertical shaft, B, which has applied to'it a bevel-gear, a, to engage with another'bevel-gear, 2, carried by a driving-shaft, C, arranged as'represented.

Fixed on the upper end of the shaft B is what we term the circular-grooved runner, D, which, on its upper surface is formed, with one or more'circular grooves 'c c, to extend concentrically around and with it. It also has, outside of such groove orgrooves, and concentric therewith, another, or narrower groove, or trough, d.

Over the said runner is the circular-grooved cap, plate E, which, on its under surface, is grooved, as shown at d d, in correspondence with the grooves c c, of the runner.

In each groove of the runner, except the outer one thereof, is a series of balls or spheres, F F, which also extend up into the grooves of the cap-plate, and

the said cap-plate is provided with a flange, or lip, e,

to extend down from it, and around the periphery of the runner.

The halls of the inner of the two series are smaller in diameter than those of the outer series, on which the cap-plate E may rest, it being clear of the inner series of balls, in manner as shown in fig. 4. I

In other words, there is, between the upper surfaces of the inner series of balls and the cap-plate,

open or clear spaces, leading from the central part of the cap-plate t0 the outer series of balls. This causes the inner series of balls to act as crushers of the material to be ground, the outer series serving subsequently to pulverize' or reduce it to a fine dust or powder.

The cap-plate is also provided with an opening, or passage, g, leading through its flange.

A guide-plate, h, is applied to the side of such open ing, and has a scraper, 1', projecting from it down into the external groove o'r trough of the runner.

Figure-7 denotes a section taken through the opening, so as to show the guidc-plate and scraper, and the groove in which the latter operates.

Furthermore, the cap-plate is held to the frame A by a series of bolts, k, which go down through ears Z, projecting from the said cap-plate.

Each of these bolts also extends through one of the upper bars of the frame A, and one of a series of helical springs, m m, arranged against suohbars.

A nut, n, is screwed on the lower end of each of the said bolts, and up .to the lower end of the spring, so as to contract the spring, and cause it to draw the cap-plate closely upon the balls, which may be in its grooves, and in those of the runner.

Through the centre of the cap-plate is an opening, 0, to which a hopper, H, may be applied, to conduct into the mill a material to be ground thereby.

A spout, I, arranged close to the lateral opening of the cap-plate, receives the ground material as it may be discharged from the runner.

In operating with the said mill, the runner is to be put in revolution horizontally.

The material to be ground or pulverized, whether such be an auriferous ore, manganese, grain, a pigment, or other substance, is to be placed in the hopper, and suffered to run into the space between the runner and cap-plate, and between the balls thereof.

During the rotary movements of the runner, each of the balls will be put in revolution, in-van'ous directions, so as with the runner and cap, and especially with the runner, to effect the breaking and pulverizing, or grinding of the material, the same being accomplished to very great advantage, and with wonderful effect.

As the material is ground to powder, or pulverized, it will be discharged by centrifugal force into the peripheral trough of the runner, from whence, by the scraper and guide, it will be driven out of the discharging-opening of the cap-plate, and. into the spout, the flange or lip of the cap serving to lice the material from passing out of the trough, except through the said opening.

The springs which press the cap down upon the balls allow the cap to yield or be forced upward by any of the balls, when it may pass over a substance without crushing it, the cap serving also to keep the balls in their due relation with each other.

This mill is admirably adapted for reducing to powder auriferons ores, as well as many materials used in the preparation or working of pigments.

\Vc are aware of the quartz-crusher, described in the United States patent, No. 11,988, granted No- "ember 28, 1854, to J W. Gochrau. In this crusher there is but one series of balls, whereas, in our mill we employ two series, and have those of the inner of diameters less than those of the outer series, as described.

We make no claim, therefore, to the invention shown in such patent, or in other words, the combination of a circular-grooved runner and a single series of balls, with a circular-grooved cap-plate. y

We claim the circular-grooved cap-plate, arranged so as not only to rest on the outer series of balls, supported by the grooved runner, but to have its inner groove over the inner series of balls out of contact therewith, or disposed with a narrow space between it and them, the same being constructed as herein described and as represented.

We also claim the combination of one or more springs, m, or the equivalent thereof, with the circular-grooved cap E, and the circular-grooved runner D, and its series of balls F, such spring, or springs, being to enable the the eircular-grooved cap, and runner, and their series of balls, arranged to operate together, as set forth.

ALMON THWING. CHAS. H. FOWLER. Witnesses:

R. H. EDDY, F. P. HALE. 

